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T-34 – Mice VS Cats – Part 12

2015-11-21

In case if you missed it, here is the previous part.

Now it’s time to talk about quality of armoured steel and manufacturing defects. Certainly both German and Soviet tanks suffered from that even for the very different reasons.

Speaking about quality, here is the real case happened on factory 183. In may 1942 Red Army started to complain they received T-34s not just a bad quality, but with a cracks in its armour straight after coming out of factory doors. The whole of the issue went to such a high level as Molotov himself. Initially everybody thought it was caused by almost starving factory workers and the lack of food. So it was send quite a lot of additional food supplies to factory workers, So much that it was more than enough by any standards. Guess if it changed anything? No it didn’t apart from having nice dinners factory workers also managed to steal part of the food supplies and even to resell it. But quality of armour didn’t improve not even an inch

This time it was so serious issue it went up to Stalin. Stalin called responsible minister and…. no he didn’t shoot him, unfortunately Stalin was very soft person. Stalin just replaced him with another minister and investigation continued. Cracks were everywhere, the length they had was anything between 50 – 1200 mm with up to 2-8 cracks on the single plate of armour, even not on welded onces.

Finally Soviets managed to find out the reason.Bad armour sheets were send from Nizhniy Tagil Iron and Steel Works factory. Having a further look it was caused by nothing else but a piss taking and workers and breaches of  technological process.

8C type of steel produced by Nizhniy Tagil Iron and Steel Works factory did not had even distribution of chemical components such as Carbon, Silica and Phosphorus. The main reason for such defects was lack of discipline and breaches in technological process. As a prime example instead of supposed 14 hours melting, alloy was melted anything between 15 – 18 hours.

As a Soviet standard before war Phosphorous content in  8C type of steel should be no more than 0,03%. With the start of war it was increase up to 0,035%. Regarding Nizhniy Tagil Iron and Steel Works factory that number was increased up to 0,040%, but later on increased even more up to 0,045%. Even then they couldn’t cope with it.

So Soviets managed to find the reason, but if they managed to fix it?) You wish. according to Molotov orders nothing was done even by 10 august 1942, but only from September 1942.

 

When it comes to German tanks, speaking about chemical composition of German armour in 1944 they did nothing wrong. On the contrary they improved it. Nevertheless their armour suffered. So why was it so if chemical composition was right?

Here is unclassified report “Metallurgical Examination of a 3-1/4″ Thick armor Plate from a German PzKw V (Panther) Tank“.

Also the to most important parts.

vanadium

Here is a typo mistake and speculation about Molybdenum while not consider proper properties of Vanadium. Also high content of carbon could replace Molybdenum.

verdict

The most important thing. In order to fix the problem all they had to do is to re temper following a water quench. That’s it! In other words due to increased production numbers Germans did not had a time for water quenching and replaced it with air quenching, but this is something could vary even on individual machine.

Did the quality of German armored steel dropped? Yes it did but not because of lack of alloy components, but because of increased production numbers or even change of technological process Germans were not able to temper properly. It is something could greatly wary on individual tank

 If you still have an interest here is the next part